.page-about{
  --ab-space: clamp(2.4rem, 6vw, 4.2rem);
  --ab-shadow: 7px 7px 0 rgba(18,61,51,.85);
}

/* ---------- 首屏 ---------- */
.page-about .ab-intro{
  padding-block: clamp(1.3rem, 3.6vw, 2.2rem) clamp(1.6rem, 4vw, 2.8rem);
}

.page-about .crumbs{
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .45rem;
  font-size: .85rem;
  color: var(--mute);
}
.page-about .crumbs a{
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .2s var(--ease);
}
.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible{ border-bottom-color: var(--cyan); }
.page-about .crumbs__sep{ color: rgba(143,167,156,.55); }

.page-about .ab-masthead{
  display: grid;
  gap: clamp(1.4rem, 3.4vw, 2.4rem);
  margin-top: clamp(1.1rem, 2.6vw, 1.8rem);
}
@media (min-width: 900px){
  .page-about .ab-masthead{
    grid-template-columns: minmax(0, 1.32fr) minmax(0, .88fr);
    align-items: end;
    gap: clamp(2rem, 4vw, 3.4rem);
  }
}

.page-about .ab-title{
  margin: 0;
  font-family: var(--font-title);
  font-size: clamp(2rem, 6.4vw, 4rem);
  line-height: 1.06;
  letter-spacing: -.02em;
  font-weight: 900;
  color: var(--paper);
}
.page-about .ab-title__hl{
  color: var(--gold);
  border-bottom: 4px solid rgba(53,224,208,.55);
  padding-bottom: .06em;
}

.page-about .ab-lede{
  margin: clamp(1rem, 2.4vw, 1.5rem) 0 0;
  max-width: 46ch;
  font-size: clamp(1rem, 2.1vw, 1.12rem);
  line-height: 1.8;
  color: var(--paper);
}

.page-about .ab-stats{
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .85rem;
}
@media (min-width: 520px){
  .page-about .ab-stats{ grid-template-columns: repeat(2, minmax(0,1fr)); }
}
.page-about .ab-stats li{
  display: flex;
  align-items: baseline;
  gap: .6rem;
  padding-top: .65rem;
  border-top: var(--bd) solid var(--line);
}
.page-about .ab-stats__num{
  flex: 0 0 auto;
  font-size: clamp(1.3rem, 3.4vw, 1.7rem);
  font-weight: 700;
  color: var(--gold);
  letter-spacing: -.01em;
}
.page-about .ab-stats__label{
  font-size: .82rem;
  line-height: 1.55;
  color: var(--mute);
}

/* ---------- 正文两栏 ---------- */
.page-about .ab-body{
  display: grid;
  gap: clamp(1.6rem, 4vw, 2.4rem);
  padding-bottom: clamp(3rem, 7vw, 5.5rem);
}
@media (min-width: 960px){
  .page-about .ab-body{
    grid-template-columns: 214px minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 3.6rem);
    align-items: start;
  }
  .page-about .ab-toc{
    position: sticky;
    top: 1.4rem;
  }
}

/* ---------- 章节目录 ---------- */
.page-about .ab-toc{
  border: var(--bd) solid var(--line);
  background: linear-gradient(170deg, rgba(27,111,99,.24), rgba(11,43,36,.65));
  padding: .85rem .95rem 1rem;
}
.page-about .ab-toc__title{
  margin: 0;
  color: var(--gold);
}
.page-about .ab-toc__list{
  list-style: none;
  margin: .7rem 0 0;
  padding: 0 0 .3rem;
  display: flex;
  gap: .45rem;
  overflow-x: auto;
  scrollbar-width: thin;
}
.page-about .ab-toc__list a{
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  white-space: nowrap;
  padding: .3rem .5rem;
  font-size: .88rem;
  color: var(--paper);
  text-decoration: none;
  border: var(--bd) solid transparent;
  transition: border-color .2s var(--ease), color .2s var(--ease);
}
.page-about .ab-toc__list a .mono{
  color: var(--cyan);
  font-size: .78rem;
}
.page-about .ab-toc__list a:hover,
.page-about .ab-toc__list a:focus-visible{
  border-color: var(--cyan);
  color: var(--cyan);
}
.page-about .ab-toc__note{
  margin: .8rem 0 0;
  padding-top: .7rem;
  border-top: var(--bd) solid var(--line);
  font-size: .74rem;
  color: var(--mute);
  letter-spacing: .06em;
}
@media (min-width: 960px){
  .page-about .ab-toc__list{
    display: grid;
    gap: .1rem;
    overflow: visible;
    padding-bottom: 0;
  }
  .page-about .ab-toc__list a{ width: 100%; }
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-content{
  min-width: 0;
}
.page-about .ab-sec{
  padding-top: clamp(1.3rem, 3vw, 2rem);
  margin-top: var(--ab-space);
  border-top: var(--bd) solid var(--line);
}
.page-about .ab-sec:first-child{
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}
.page-about .ab-sec__head{
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .5rem .85rem;
  margin-bottom: 1.1rem;
}
.page-about .ab-sec__no{
  color: var(--gold);
  font-size: .82rem;
  letter-spacing: .14em;
  border: var(--bd) solid var(--line);
  padding: .16rem .45rem;
}
.page-about .ab-sec h2{
  margin: 0;
  font-family: var(--font-title);
  font-size: clamp(1.45rem, 3.6vw, 2.25rem);
  line-height: 1.22;
  letter-spacing: -.01em;
  font-weight: 800;
  color: var(--paper);
}
.page-about .ab-sec p{
  margin: 0 0 1rem;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--paper);
}
.page-about .ab-sec > p:last-child{ margin-bottom: 0; }

/* ---------- 图 ---------- */
.page-about .ab-figure{
  margin: 0 0 1.3rem;
  border: var(--bd) solid var(--line);
  box-shadow: var(--ab-shadow);
  background: linear-gradient(150deg, var(--teal), var(--panel) 65%);
  overflow: hidden;
}
.page-about .ab-figure img{
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .ab-figure__cap{
  display: block;
  padding: .55rem .75rem;
  font-size: .74rem;
  letter-spacing: .04em;
  color: var(--mute);
  border-top: var(--bd) solid var(--line);
  background: rgba(7,26,22,.55);
}

/* ---------- 原则卡 ---------- */
.page-about .ab-principles{
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}
@media (min-width: 700px){
  .page-about .ab-principles{ grid-template-columns: repeat(3, minmax(0,1fr)); }
}
.page-about .ab-principles li{
  padding: 1rem 1rem 1.1rem;
  border: var(--bd) solid var(--line);
  background: linear-gradient(158deg, rgba(27,111,99,.3), rgba(7,26,22,.1));
  transition: border-color .24s var(--ease), transform .24s var(--ease), box-shadow .24s var(--ease);
}
.page-about .ab-principles li:hover,
.page-about .ab-principles li:focus-within{
  border-color: var(--cyan);
  transform: translate(-3px, -3px);
  box-shadow: 6px 6px 0 rgba(53,224,208,.2);
}
.page-about .ab-principles h3{
  margin: 0 0 .5rem;
  font-size: 1rem;
  font-weight: 800;
  color: var(--gold-lit);
  letter-spacing: -.005em;
}
.page-about .ab-principles p{
  margin: 0;
  font-size: .9rem;
  line-height: 1.72;
  color: var(--mute);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline{
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0 0 0 1.5rem;
  border-left: var(--bd) solid var(--line);
}
.page-about .ab-node{
  position: relative;
  padding-bottom: .8rem;
}
.page-about .ab-node:last-child{ padding-bottom: 0; }
.page-about .ab-node::before{
  content: "";
  position: absolute;
  left: -1.5rem;
  top: .95rem;
  width: 10px;
  height: 10px;
  transform: translateX(-50%) rotate(45deg);
  background: var(--ink);
  border: var(--bd) solid var(--gold);
}
.page-about .ab-node details{
  border: var(--bd) solid transparent;
  transition: border-color .22s var(--ease), background-color .22s var(--ease);
}
.page-about .ab-node details[open]{
  border-color: var(--line);
  background: rgba(11,43,36,.55);
}
.page-about .ab-node summary{
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .35rem .7rem;
  padding: .4rem .6rem;
  list-style: none;
  cursor: pointer;
}
.page-about .ab-node summary::-webkit-details-marker{ display: none; }
.page-about .ab-node summary::after{
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: .9rem;
  color: var(--gold);
}
.page-about .ab-node details[open] summary::after{ content: "－"; color: var(--cyan); }
.page-about .ab-node summary:hover .ab-node__title,
.page-about .ab-node summary:focus-visible .ab-node__title{ color: var(--cyan); }
.page-about .ab-node__phase{
  font-size: .74rem;
  letter-spacing: .06em;
  color: var(--cyan);
  border: var(--bd) solid rgba(53,224,208,.42);
  padding: .08rem .38rem;
}
.page-about .ab-node__title{
  font-size: 1rem;
  font-weight: 800;
  color: var(--paper);
  transition: color .2s var(--ease);
}
.page-about .ab-node__body{
  margin: 0;
  padding: .2rem .7rem .95rem;
  font-size: .94rem;
  line-height: 1.78;
  color: var(--mute);
}

/* ---------- 团队矩阵 ---------- */
.page-about .ab-team{
  list-style: none;
  margin: 1.3rem 0 1.2rem;
  padding: 0;
  display: grid;
  gap: 1rem;
}
@media (min-width: 760px){
  .page-about .ab-team{ grid-template-columns: repeat(2, minmax(0,1fr)); }
}
.page-about .ab-team__cell{
  padding: 1rem 1.05rem 1.15rem;
  border: var(--bd) solid var(--line);
  border-top-width: 4px;
  border-top-color: rgba(201,162,75,.7);
  background: var(--panel);
  box-shadow: 4px 4px 0 rgba(18,61,51,.6);
}
.page-about .ab-team__no{
  display: inline-block;
  margin-bottom: .45rem;
  font-size: .78rem;
  letter-spacing: .12em;
  color: var(--gold);
}
.page-about .ab-team__cell h3{
  margin: 0 0 .45rem;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--paper);
}
.page-about .ab-team__cell p{
  margin: 0;
  font-size: .92rem;
  line-height: 1.75;
  color: var(--mute);
}
.page-about .ab-note{
  font-size: .82rem;
  line-height: 1.7;
  color: var(--mute);
  padding-left: .85rem;
  border-left: 3px solid var(--copper);
}

/* ---------- 生态列表 ---------- */
.page-about .ab-eco{
  list-style: none;
  margin: 1.2rem 0 0;
  padding: 0;
}
.page-about .ab-eco li{
  display: grid;
  gap: .2rem;
  padding: .85rem 0;
  border-top: var(--bd) solid var(--line);
}
.page-about .ab-eco li:last-child{ border-bottom: var(--bd) solid var(--line); }
@media (min-width: 700px){
  .page-about .ab-eco li{
    grid-template-columns: 150px minmax(0,1fr);
    gap: 1.2rem;
    align-items: baseline;
  }
}
.page-about .ab-eco__key{
  font-family: var(--font-mono);
  font-size: .82rem;
  letter-spacing: .06em;
  color: var(--gold-lit);
}
.page-about .ab-eco li p{
  margin: 0;
  font-size: .94rem;
  line-height: 1.75;
  color: var(--mute);
}

.page-about .ab-badges{
  display: grid;
  gap: .7rem;
  margin-top: 1.3rem;
}
@media (min-width: 700px){
  .page-about .ab-badges{ grid-template-columns: repeat(2, minmax(0,1fr)); }
}
.page-about .ab-badges__item{
  display: flex;
  align-items: baseline;
  gap: .7rem;
  margin: 0;
  padding: .8rem .9rem;
  font-size: .92rem;
  line-height: 1.65;
  color: var(--paper);
  border: var(--bd) solid var(--line);
  background: linear-gradient(140deg, rgba(217,142,95,.16), rgba(11,43,36,.9));
}
.page-about .ab-badges__item .mono{
  flex: 0 0 auto;
  font-size: 1rem;
  font-weight: 700;
  color: var(--copper);
}

/* ---------- iOS 版块 ---------- */
.page-about .ab-ios{
  display: grid;
  gap: 1.2rem;
  margin-bottom: 1.3rem;
}
@media (min-width: 820px){
  .page-about .ab-ios{
    grid-template-columns: minmax(0,1fr) minmax(0,.82fr);
    align-items: start;
    gap: 1.6rem;
  }
}
.page-about .ab-ios__text p{
  margin: 0 0 .9rem;
  font-size: .98rem;
  line-height: 1.82;
  color: var(--paper);
}
.page-about .ab-ios__text p:last-child{ margin-bottom: 0; }
.page-about .ab-ios .ab-figure{ margin-bottom: 0; }

.page-about .ab-steps{
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .6rem;
}
.page-about .ab-steps li{
  display: grid;
  grid-template-columns: 2.2rem minmax(0,1fr);
  gap: .1rem .75rem;
  padding: .8rem .9rem;
  border: var(--bd) solid var(--line);
  border-left-width: 4px;
  border-left-color: var(--cyan);
  background: rgba(11,43,36,.7);
  font-size: .93rem;
  line-height: 1.7;
  color: var(--mute);
}
.page-about .ab-steps__no{
  grid-row: span 2;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--gold);
  line-height: 1.2;
}
.page-about .ab-steps strong{
  color: var(--paper);
  font-weight: 800;
}

/* ---------- 收束 ---------- */
.page-about .ab-close{
  margin-top: var(--ab-space);
  padding: clamp(1.3rem, 4vw, 2.4rem);
  border: var(--bd) solid var(--gold);
  background: linear-gradient(135deg, rgba(27,111,99,.42), rgba(7,26,22,.9) 68%);
  box-shadow: var(--ab-shadow);
}
.page-about .ab-close h2{
  margin: 0 0 .7rem;
  font-family: var(--font-title);
  font-size: clamp(1.3rem, 3.2vw, 1.9rem);
  line-height: 1.3;
  font-weight: 800;
  color: var(--paper);
}
.page-about .ab-close p{
  margin: 0 0 1.2rem;
  max-width: 54ch;
  font-size: .96rem;
  line-height: 1.8;
  color: var(--mute);
}
.page-about .ab-close__links{
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
}

.page-about .ab-top{
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  margin-top: 1.6rem;
  padding-bottom: .2rem;
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .08em;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 2px solid rgba(53,224,208,.35);
}
.page-about .ab-top::before{ content: "↑"; }
.page-about .ab-top:hover,
.page-about .ab-top:focus-visible{ border-bottom-color: var(--cyan); }

@media (prefers-reduced-motion: reduce){
  .page-about *{
    transition: none !important;
    animation: none !important;
  }
}
</main>